| 摘要 |
PROBLEM TO BE SOLVED: To check an enlargement of a device, and improve excavating efficiency while surely receiving excavating reaction in a tunnel excavator. SOLUTION: A support box 34 is movably supported in a tip part of a spoke 22 of a cutter head 19 by a hydraulic jack 36. An over-cutter 28 is rotatably supported in its slant attitude in this support box 34. A receiving part 38 is formed by extending the cutter head 19 up to the reverse side of the support box 34 so that the excavating reaction of the cover-cutter 28 is dispersively supported by the hydraulic jack 36 and the receiving part 38. |
